From: Cetin Baloglu (
Date: Tue May 10 2005 - 09:47:59 CDT

Hi ,

I want to calculate radius of gyration of a xyz trajectory for each
frame, measure rgyr command seems to do it alone for the active frame .

when I change the frame one by one with animate next command, measure
rgyr [atomselect top "name CA"] command works , but when I try to give
these in a for loop

mol load xyz
set a {}
for { set i 0 } { $i <=100 } {incr i} {
animate next # or animate goto $i
lappend a [measure rgyr [atomselect top "name CA"]]

Here I want to see 100 different rgyr value but the list a contains 100
same value.

I am new in tcl and vmd scripting and I don't know the hints yet.


Cetin Baloglu